Two Large Studies Show IPM's Monthly Vaginal Ring Helps Protect Women Against HIV
First long-acting HIV prevention method for women reduced infections by approximately 30% overall, with differences in efficacy by age and level of use; IPM to seek regulatory approval for investigational product
BOSTON (Feb. 22, 2016) — In an important scientific achievement for women’s health, two large Phase III clinical trials — The Ring Study and ASPIRE — have shown that a monthly vaginal ring containing the antiretroviral drug (ARV) dapivirine can safely help prevent HIV-1 infection in women. Developed by the nonprofit International Partnership for Microbicides (IPM), the monthly ring is the first long-acting HIV prevention method designed for women, who bear the greatest burden of the global HIV/AIDS epidemic. IPM plans to apply for regulatory approval to license the product.
The Ring Study, led by IPM, showed that the monthly dapivirine ring safely reduced HIV infection overall by 31 percent compared to a placebo. Similar results were seen in ASPIRE, led by the US National Institutes of Health-funded Microbicide Trials Network (MTN), which found that the ring safely reduced infection by 27 percent overall. This is the first time two Phase III studies have confirmed statistically significant efficacy for a microbicide to prevent HIV.
Notably, both studies saw important differences in efficacy by age and consistency of ring use, or adherence. ASPIRE showed that the ring reduced HIV risk by 61 percent in women older than age 25, and in a post-hoc analysis by 56 percent in women older than 21, who also appeared to use the ring more consistently. These findings were statistically significant and supported by a trend in The Ring Study which also showed higher efficacy (37 percent) for women over 21.
Conversely, little to no protection was seen in women ages 18-21 across both studies — 15 percent in The Ring Study and no protection in ASPIRE. This underscores the urgent need to overcome barriers to HIV prevention for the youngest women. IPM and MTN are working to understand how ring use, and potential biological and other factors may have influenced the different levels of protection seen by age in these studies.
Results from The Ring Study and ASPIRE were announced today at the annual Conference on Retroviruses and Opportunistic Infections (CROI) in Boston, Massachusetts.
Read the full release.
Learn more about the ring and today's results